Research On The Key Technology Of The Topside Hoisting Scheme Design Of Mega Offshore Platform

Development and utilization of marine energy is promoting the offshore platforms larger than before, and making the design and construction of offshore platforms more difficult as well. Mega offshore platforms not only increase the volume and weight of the upper deck, but also increase the height of the upper the upper deck. Therefore, in the large offshore platforms mating process, how to complete topside lifting safely and efficiently become the focus of ship design and construction. This paper focuses on the topside lifting technology of mega offshore platform mating, and investigates the recent domestic and overseas cases of mega offshore platform topside lifting and jacking which include the topside of semi-submersible drilling platform, TLP, jacket platform, and special form platform. It conducts research on the two main ways (lifting and jacking) of mega offshore platform topside lifting, whose technical characteristics is analyzed in terms of equipment, capability and process, which sums up the technological superiority of lifting and jacking by comparing the lifting weight, height, security and economic factors. In order to select the appropriate lifting equipment, it proposes a safety factor of lifting process. The paper discusses the mega offshore platform topside lifting and jacking technical characteristics and development direction, which is proposed a reliable theoretical basis and reference for the mega offshore platforms mating.This paper explains how to determine the lifting arrangement of space rationally and how to select the hoisting points of the topside reasonably. It proposes the lifting load of the simplified model and the simplified calculation method. It analyzes the advantages and disadvantages of hoisting tower form improve the process, and through the practical case of the design method of the hoisting scheme was verified. For the safety evaluation of hoisting construction scheme, this paper applies the comprehensive safety assessment method bases on the view of risk. According to the specific process of construction, this paper puts forward the possible risks and the corresponding solutions to improve the safety of the construction process effectively. Applying the risk analysis method to the evaluation of, a feasible evaluation method for the safety of the hoisting schemes are proposed, which is of great importance. According to the diversity issues of design of the mega offshore platform's topside hoisting schemes, the fuzzy comprehensive evaluation method is applied to comprehensive evaluation of the topside hoisting schemes by comparing the technology, economy and safety factor. The weight of each index is determined by analytic hierarchy process. The evaluation indexes are put forward and the calculation method is given according to the characteristics of the scheme, which provide the theoretical basis for the design and evaluation of the hoisting scheme. And a comprehensive evaluation program of hoisting scheme is developed with VB.NET, which is convenient for program evaluation.